Thanks for reading Your First 1000 Copies and I’m excited you’re trying out the transcriber method for creating content!
To make the phone calls, I highly recommend Skype. It’s free if you are calling someone else on Skype and very reasonable if you are calling a phone number.
To record the phone calls, I recommend the Evaer recorder for Windows/PC and the Ecamm recorder for Mac.
I find Skype to offer iffy quality.